The present invention relates to a process for the generation of a computer image of a three-dimensional object, particularly those objects that have a special-effect coating applied thereto.
The computer-aided, three-dimensional image of an actually existing or virtual three-dimensional object belongs to the prior art. The observer be given an impression of the optical effect of a simple (e.g., single-color) version of the three-dimensional object (cf. brochure on OPUS software version 3.2 from Opticore). However, a realistic computer image of a three-dimensional object in which the intended effects of a special-effect coating (e.g., coatings that change color or hue depending on the viewing angle and/or illumination angle) can be observed is not known in the prior art. Rather, it was necessary to apply the special-effect coating concerned to an actual prototype of the object, or the object itself in order to be able to experience the full optical effect of the coating. This manufacture of prototypes, for example, in the motor vehicle sector, is not economically viable.
There is a need to provide a process which permits the realistic representation on computer of three-dimensional objects provided with special-effect coatings. More particularly, it should be possible to apply the process to the generation of a computer image of motor vehicle bodies and motor vehicle body parts provided with special-effect coatings.
The invention comprises a process for the generation of a computer image of a three-dimensional object having a special-effect coating thereon, comprising the steps of, in appropriate order:
a) coating a test panel with a special-effect coating;
b) taking a plurality of angle-dependent calorimetric measurements of the coating;
c) storing the colorimetric data in a datafile with assignment of the corresponding angles;
d) facetting the visible surface(s) of a three-dimensional object by computer into a sufficient number of flat polygonal areas each being sufficiently small for the sufficiently accurate description of the surface topography;
e) assigning the calorimetric data to each individual polygonal area by computer as a function of the position of an observer and at least one illumination source; and
f) assembling the polygonal areas into a computer image of the three-dimensional object with a visually perceptible special-effect coating thereon.